Certified Open Hardware Licenses
"It is strongly recommended that you use the Recommended Licenses rather than the licenses on this list. The Recommended Licenses have been chosen to provide a minimal set of licenses, which are all compatible with each other, and which thus reduce the legal load upon the entire community. When you choose a license that isn't on the recommended list, you increase the legal load to developers and users unnecessarily.
The Certified License list has not been set yet. This list will be developed according to the Certified Open Hardware License Approval Process.
Note that Hardware Isn't Generally Copyrightable. Thus, there are severe limitations upon the enforcement of the licenses of hardware designs that do not exist for licenses applied to software." (http://wiki.openhardware.org/Certified_Licenses)